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Simple Handlebars.js helpers
/*! ******************************
Handlebars helpers
*******************************/
// debug helper
// usage: {{debug}} or {{debug someValue}}
// from: @commondream (http://thinkvitamin.com/code/handlebars-js-part-3-tips-and-tricks/)
Handlebars.registerHelper("debug", function(optionalValue) {
console.log("Current Context");
console.log("====================");
console.log(this);
if (optionalValue) {
console.log("Value");
console.log("====================");
console.log(optionalValue);
}
});
// return the first item of a list only
// usage: {{#first items}}{{name}}{{/first}}
Handlebars.registerHelper('first', function(context, block) {
return block(context[0]);
});
// a iterate over a specific portion of a list.
// usage: {{#slice items offset="1" limit="5"}}{{name}}{{/slice}} : items 1 thru 6
// usage: {{#slice items limit="10"}}{{name}}{{/slice}} : items 0 thru 9
// usage: {{#slice items offset="3"}}{{name}}{{/slice}} : items 3 thru context.length
// defaults are offset=0, limit=5
// todo: combine parameters into single string like python or ruby slice ("start:length" or "start,length")
Handlebars.registerHelper('slice', function(context, block) {
var ret = "",
offset = parseInt(block.hash.offset) || 0,
limit = parseInt(block.hash.limit) || 5,
i = (offset < context.length) ? offset : 0,
j = ((limit + offset) < context.length) ? (limit + offset) : context.length;
for(i,j; i<j; i++) {
ret += block(context[i]);
}
return ret;
});
// return a comma-serperated list from an iterable object
// usage: {{#toSentence tags}}{{name}}{{/toSentence}}
Handlebars.registerHelper('toSentence', function(context, block) {
var ret = "";
for(var i=0, j=context.length; i<j; i++) {
ret = ret + block(context[i]);
if (i<j-1) {
ret = ret + ", ";
};
}
return ret;
});
// format an ISO date using Moment.js
// http://momentjs.com/
// moment syntax example: moment(Date("2011-07-18T15:50:52")).format("MMMM YYYY")
// usage: {{dateFormat creation_date format="MMMM YYYY"}}
Handlebars.registerHelper('dateFormat', function(context, block) {
if (window.moment) {
var f = block.hash.format || "MMM Do, YYYY";
return moment(Date(context)).format(f);
}else{
return context; // moment plugin not available. return data as is.
};
});
@mygittyhubby
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mygittyhubby commented Oct 17, 2017

where to put the Handlebars.registerHelper function ? which file ? I've been searching the internet and couldn't find the answer, I kept getting "Missing Helper" error messages

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